The present invention generally relates to medical devices and more specifically relates to medically implantable pumps particularly those used in conjunction with gastric banding systems for controlling obesity.
Adjustable gastric banding procedures have provided a highly effective and substantially less invasive alternative to gastric bypass surgery and other conventional surgical weight loss procedures for treating, for example, reducing or eliminating, obesity and obesity-related diseases. It has been recognized that sustained weight loss can be achieved through a laparoscopically-placed gastric band, for example, the LAP-BAND® gastric band or the LAP BAND AP® gastric band. Generally, the LAP-BAND® is placed about the cardia, or upper portion, of a patient's stomach to form a stoma that restricts the passage of food into a lower portion of the stomach. When the stoma is of an appropriate size, food held in the upper portion of the stomach provides a feeling of satiety or fullness that discourages overeating. Unlike gastric bypass procedures, laparoscopic gastric banding procedures are reversible and require no permanent modification of the gastrointestinal tract.
Over time, the stoma created by the gastric band may need adjustment in order to maintain the appropriate size which is preferably neither too restrictive nor too passive. Accordingly, the LAP-BAND® system provides a subcutaneous fluid access port connected to an expandable or inflatable portion of the band. By adding or removing fluid to or from the inflatable portion by means of a hypodermic needle inserted into the access port, the effective size of the band can be adjusted to provide a tighter or looser constriction.
Naturally, it would be desirable to allow for adjustment of the band constriction without the use of a hypodermic needle. Thus, automatically adjustable gastric banding systems as well as remotely adjustable gastric banding systems have been proposed.
Birk, U.S. Patent Application Publication No. 2007/0156013, commonly assigned herewith and incorporated in its entirety herein by this specific reference, discloses an automatically adjustable gastric band system including an adjustment assembly that includes a sensor for sensing fluid pressure in the expandable portion of a gastric band. The adjustment assembly further includes an implantable pump connected to the expandable portion, and a controller for operating the pump to allow for automatic adjustment the volume of the fluid in the band based on the sensed fluid pressure.
Birk et al. U.S. Patent Application Publication No. 2007/0265645 commonly assigned herewith and incorporated in its entirety herein by this specific reference, discloses a self-regulating gastric band adjustment assembly including an implantable fluid reservoir for containing a volume of the fluid useful for adjusting the band.
Coe, U.S. Pat. No. 7,338,433, commonly assigned herewith and incorporated in its entirety herein by this specific reference, discloses a remotely controllable gastric banding system including a pressurized reservoir with valves, and a controller for remotely controlling the valves from outside the patient.
There continues to remain a need for more effective implantable pump systems for use with adjustable gastric bands, particularly such implantable pump systems including calibration.